The present invention relates to a dispensing container for semi-solid or pasty substances such as lipstick, glue, polish, etc, shaped as a stick, the container having a cup-like holder in which the stick of substance is fixed. The invention particularly refers to economical and wasteless-use designs of such a container.
In conventional containers of the above type, an axially movable cup-like holder carrying a stick of substance is usually mounted in an intermediate cylinder fitted within an outer sleeve in a manner enabling the rotation of the cylinder and the sleeve relative to each other. The container has further a base portion integral with the intermediate cylinder and protruding from the outer sleeve, to be held by the user. To enable the axial movement of the holder with respect to the intermediate cylinder to expose and hide the stick of substance, the intermediate cylinder is formed with at least one axial slit, the outer sleeve has at least one helical groove formed in its internal surface and the holder is formed with at least one radially protruding pin passing through the slit in the intermediate cylinder and received in the helical grooves of the outer sleeve. The substance holder, the intermediate cylinder and the outer sleeve cooperate in such a manner that, when the intermediate cylinder with the base portion and the outer sleeve are rotated relative to each other in a predetermined direction, the holder advances axially towards the open end of the intermediate cylinder to expose the stick of substance for usage. When the relative rotation between the outer sleeve and the intermediate cylinder with the base is provided in the opposite direction, the substance holder is retracted back to hide the stick of substance for safe keeping.
During application, the stick of substance is expected to sustain axial and radial forces, and not to deform or break. This necessarily limits the usable free stick length to about 2-5 cm, depending on the stick""s diameter, material, and mode of application. Furthermore, for the stick of substance not to fall out of the holder under these forces, its rear end is usually tightly inserted in the holder to about 1xe2x88x9d1.5 cm of its length, which therefore cannot be used. Thus, a significant proportion of the substance is practically wasted for the user.
To solve the above problem, U.S. Pat. No. 5,893,672 suggests an extractor for recovering and dispensing the unusable portion of a pasty substance located in a holder of an original packaging. This device is a stand-alone dispenser comprising a casing, a cover, and a piston-like bottom, which has to be filled with the remains of the pasty material from the original packaging. The extractor has to fit quite precisely in the opening of the original packaging and, therefore, for different shapes of original packaging different extractors are required.
U.S. Pat. No. 3,677,654 discloses a lipstick dispenser which is based on the conventional design described above, but has a holder with an independently movable bottom and an outer cylinder with a groove at its internal surface, that has a conventional helical section and a non-conventional annular section adjacent to the open end of the container. The movable bottom is formed with a radially protruding pin that passes though the holder""s axial slit and is received within the outer sleeve""s helical groove, cooperating with them in the same manner as the holder""s pins that are responsible for the axial movement of the holder. Thus, when the holder, together with the movable bottom, is driven to the extreme exposed position by the relative rotation of the outer sleeve with respect to the intermediate cylinder, the holder""s pins enter the annular portion of the groove whilst the pin of the movable bottom is still engaged with the helical portion. In this state, a further rotation of the outer sleeve relative to the intermediate cylinder will cause the pin of the movable bottom to advance along the holder with the holder being kept still, and eject the remainder of the lipstick for ultimate use. The reverse rotation of the sleeve relative to the intermediate cylinder moves the bottom in the rearward direction of the container. During this movement the holder is supposed to suck the lipstick back so as to retract the entire holder-bottom assembly. However, to ensure the suction of the lipstick by the movable bottom, there should be provided an airtight connection between this bottom and the holder, and between the holder and the lipstick, which is hardly achievable. Therefore, chances are rather high that, on the way back, the bottom will detach from the lipstick material, which will then remain in unstable position before the next use.
It is the object of the present invention to provide a new dispensing container for semi-solid or pasty substances such as lipstick, glue, polish, etc, shaped as a stick, enabling the convenient and efficient usage of the substance substantially along the entire stick length thereof.
The present invention provides a container for keeping and dispensing a semisolid or pasty substance such as lipstick or glue, comprising a substance holder, an intermediate cylinder with a base, and an outer sleeve, which have a design and manner of interaction basically the same as in conventional dispensing containers, the container however having additional features enabling economical and wasteless-use of its substance. In particular, in the container of the present invention, the substance holder has a bottom movable relative thereto, the container being so designed as to enable the advancement of the bottom towards the container""s open end and self-arresting the bottom against its back movement relative to the holder. This enables the bottom of the holder to be fixed in an advanced position relative to the holder, while the container may be further used in the normal way, without the user feeling any resistance to the usual manipulation, whereby to expose the substance stick for application and to conceal it after use, the substance holder is axially displaced by the rotation of the outer sleeve and the intermediate cylinder relative to each other.
In accordance with the present invention, the advancement of the bottom relative to the substance holder is preferably provided by a pushing element capable of applying to the bottom a central axial force directed from the base of the intermediate cylinder.
The self-arresting of the bottom in its advanced position is preferably provided by the interaction of either the movable bottom or the pushing element with the walls of the substance holder.
The container according to the present invention may have substance holders with a specific novel design of their bottom wall enabling the movement of this wall relative to the side walls of the substance holder. Alternatively, the substance holder 30 may have a conventional cup-like design with integral side and bottom walls and an additional movable bottom formed as a separate element inserted in the substance holder to cover its own integral bottom wall, prior to the fixation of the stick of substance therein.